We recorded a total of 2,922 individuals belonging to 38 taxa (Table). The highest number of taxa per plot was 24, and the lowest was 20. The sample coverage exceeded 0.97 suggesting that a substantial proportion of the species present in the area was sampled.
Table. Species list, life forms and mean abundance [ind.m2] of Collembola in plots bioturbated by wild boars (B1, B2, B3) and control plots (C1, C2, C3). Life forms: a, atmobiotic; ep, epedaphic; eu, euedaphic; h, hemiedaphic. Life-form classification is according to Babenko et al. (1988) and Potapov et al. (2016).
Taxa | Life form | C1 | C2 | C3 | B1 | B2 | B3 |
Xenylla maritima Tullberg, 1869 | ep | 450 | 400 | 50 | 267 | 233 | 300 |
Xenylla sp. juv. | ep | 67 | - | - | - | - | - |
Willemia anopthalma Börner, 1901 | eu | 33 | 17 | 33 | - | - | - |
Friesea claviseta Axelson, 1900 | ep | 533 | 50 | 1717 | - | 133 | - |
F. truncata Cassagnau, 1958 | ep | 950 | 50 | - | 317 | - | 67 |
Friesea sp. juv. | ep | 17 | 17 | - | 17 | 17 | - |
Pseudachorutes dubius Krausbauer, 1898 | ep | - | 33 | 17 | - | - | 17 |
Pseudachorutes corticicolus (Schäffer, 1896) | ep | 17 | - | - | - | - | - |
Pseudachorutes sp. juv. | ep | 33 | 17 | 17 | 33 | - | 17 |
Micranurida pygmea Börner, 1901 | h | 50 | - | 17 | - | 17 | - |
Neanura muscorum (Templeton, 1835) | h | 133 | 283 | 117 | 567 | 233 | 433 |
Neanuridae juv. | h | 200 | 483 | 133 | 17 | 133 | 50 |
Micraphorura absoloni (Börner, 1901) | eu | - | 33 | 17 | - | 50 | 33 |
Mesaphorura yosii Rusek, 1967 | eu | - | - | 33 | - | - | - |
Anurophorus atlanticus Fjellberg, 1974 | ep | - | 17 | 500 | 17 | - | 17 |
A. laricis Nicolet, 1842 | ep | - | 33 | - | 17 | 100 | 17 |
A. septentrionalis (Pallisa, 1966) | ep | 3483 | - | 683 | 83 | - | 1083 |
Anurophorus sp. juv. | ep | 300 | 17 | 417 | 33 | - | 550 |
Folsomia quadrioculata (Tullberg, 1871) | h | 17 | - | 800 | - | - | 33 |
Proisotoma minima (Tullberg, 1871) | h | - | - | - | - | 17 | - |
Isotomiella minor (Schäffer, 1896) | eu | 67 | 100 | 600 | 33 | 33 | 100 |
Parisotoma notabilis (Schäffer, 1896) | h | 1767 | 1467 | 4383 | 850 | 350 | 783 |
Desoria tolya Fjellberg, 2007 | ep | 633 | 17 | 467 | 583 | 233 | 233 |
Desoria trispinata (Mac Gillivray, 1896) | ep | - | - | 3850 | 350 | - | 183 |
Desoria sp. juv. | ep | 2817 | 3367 | 3233 | 17 | 717 | 267 |
Tomoceridae juv. | ep | - | - | - | - | 17 | - |
Orchesella bifasciata Nicolet, 1841 | a | - | 83 | 133 | 50 | 17 | 183 |
O. flavescens (Bourlet, 1839) | a | - | 17 | - | - | - | - |
O. multifasciata (Stscherbakow, 1898) | a | - | - | - | 83 | - | - |
Orchesella sp. juv. | a | - | 17 | 33 | - | - | - |
Entomobrya corticalis (Nicolet, 1841) | a | - | - | - | 33 | 33 | 267 |
E. multifasciata (Tullberg, 1871) | a | 67 | - | - | 67 | - | - |
Willowsia buski (Lubbock, 1869) | a | - | - | - | - | 17 | - |
Lepidocyrtus lignorum (Fabricius, 1775) | ep | 83 | 467 | 1467 | 83 | 100 | - |
Pseudosinella zygophora (Schille, 1908) | h | 100 | 267 | - | - | - | - |
Entomobyidae juv. | a | 33 | 67 | - | 83 | 50 | 17 |
Megalothorax minimus (Willem, 1900) | eu | - | - | 33 | - | - | - |
Arrhopalites sp. juv. | h | - | 17 | - | - | 17 | - |
The soil moisture was higher in the grubbed plots than in the control plots (Fig. 1). The average water content was 5.56% and 8.91%, respectively (Two-way ANOVA SS = 0.36, F = 27.72 p < 0.0001). Differences among replicates were nonsignificant (SS = 0.064, F = 2.48 p = 0.105), and there was no interaction between plot type and replicate (SS = 0.01, F = 0.37 p = 0.6).
The abundance of Collembola in plots bioturbated by wild boar was significantly lower than that in control plots (two-way ANOVA: SS = 1508.0, F = 40.25, p < 0.0001) (Fig. 2). There was no significant difference between spring and autumn (SS = 140.0, F = 3.74, p = 0.06), and there was no interaction between season and rooting (SS = 46.7, F = 1.25, p = 0.27). The average abundance in the grubbed plots was more than 3.6 thousand per m2, while that in the non-grubbed plots was approximately 12,6 thousand per m2 (Fig. 2).
Composition of the collembolan assemblages in the rooted plots differed distinctly from those in the control plots (Fig. 3). However, this difference was noticeable only for spring, while the structure of the collembolan assemblages during autumn was similar in both types of plots. The differences were confirmed by PERMANOVA (F = 7.23, p < 0.001), and the model explained 40.4% of the variance in the data. The assemblages in the bioturbation-spring (BS) plots differed from all other assemblages (control-spring (CS): F = 8.74, p < 0.006; control-autumn (CA): F = 5.61, p > 0.006; bioturbation-autumn (BA): F = 6.17, p > 0.006) as well as the CS assemblages (CA: F = 10.49, p > 0.006; BA: F = 11.97, p > 0.006). Autumn data revealed no significant differences between the BA and CA plots (F = 2.36, p = 0.126).
The average number of species per sample was significantly higher in the control plots than in the rooted plots (Two-way ANOVA SS = 81.0, F = 15.25, p = 0.0005) (Fig. 4).
Samples collected in autumn were richer in species than those collected in spring (SS = 87.11, F = 16.40, p = 0.003). However, there was no significant interaction between disturbance and season (SS = 0.44, F = 0.08, p = 0.78). Total species richness achieved the highest values on the control plots in autumn and the lowest on bioturbated plots in spring (Fig. 5).
However, exponential Shannon’s and inverse Simpson’s indexes reached higher values on bioturbated plots than on control plots both in spring and autumn. Accumulation curves suggest that lower species richness is a result of the low number of individuals in the grubbed plots and possible lower species detection.
Rooting by wild boars significantly influenced the life-form structure of the assemblages compared to those in the control plots (Chi square = 110.73, df = 3, p < 0.0001). The abundance of atmobiotic and hemiedaphic species was higher in grubbed plots, while the abundance of epedaphic Collembola was lower (Fig. 6).